Musical instrument.



M. S. WRIGHT.

MUSICAL INSTRUMENT.

APPLIOATION FILED JULY 11,1903.

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M. S. WRIGHT.

MUSIGAL INSTRUMENT.

APPLIOATION FILED JULY 11,1903.

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M. S. WRIGHT.

MUSIGAL INSTRUMENT.

APPLICATION FILED JULY 11,1903.

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MORRIS S. WRIGHT, OF WORCESTER, MASSACHUSETTS.

MUSICAL INSTRUMENT.

Specification of Letters Patent.

Patented Sept. 5, 1911.

Application filed July 11, 1903. Serial No. 165,192.

To all whom it may concern:

Be it known that I, MORRIS S. WRIGHT, a citizen of the United States, residing at Worcester, in the county of lVorcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Musical Instruments, of which the following is a specification, accompanied by drawings forming a part of the same.

My invention relates to a pneumatic mechanism for playing keyboard musical instruments, such as pianos, and it consists in the construction and arrangement of parts as hereinafter described and illustrated in the accompanying drawings; the novel features being pointed out in the anneXed claims.

Figure 1 of the accompanying drawings represents in side elevation so much of the actuating mechanism for playing a piano or similar keyboard instrument as is necessary to illustrate the nature of my present invention, a portion being shown in sectional view on lines 11, Fig. 2. Fig. 2 is a front view of the same removed from its inclosing case. Fig. 3 is a vertical sectional view on line 83, Fig. 2. Fig. 4 is a top view of one of the primary and one of the motor pneumatics with their connected parts, and Fig. 5 is a detached sectional view of a primary pneumatic showing a modified form of construction.

Similar reference letters and figures refer to similar parts in the different views.

My present invention relates to that class of actuating mechanism for depressing the keys of a keyboard musical instrument in which the motive power for depressing the keys is produced by atmospheric pressure acting against one side of a flexible diaphragm upon the opposite side of which the pressure has been reduced by the exhaustion of air therefrom, such actuating diaphragm forming a part of whatv is known as the motor pneumatic. The exhaustion of air in this class of instruments is controlled by a valve mechanism in which the valves are actuated by a second air operated diaphragm forming a part of what is termed as the primary pneumatic. The valve operating diaphragm of the primary pneumatic is actuated by air pressure as air is admitted thereto through an opening in a tracker board, which is opened and closed by the passage over it of a perforated music sheet. In the operation of the mechanism air is exhausted from one side of the diaphragms of the motor and primary pneumatics by means of an inclosed vacuum chamber communicating with the motor and primary pneumatics, and also communicating with means for exhausting the air therefrom, usually a pumping bellows operated by a pedal. The varying force with which the keys of the musical instruments are depressed in crescendo and diminuendo passages, or accented notes, is produced by varying the vacuum in the vacuum chamber, and in order to secure delicate and accurate graduations of pressure upon the diaphragm of the motor pneumatic, the eX- haustion of air from the vacuum chamber should respond quickly and accurately to the action of the pumping bellows, and the valve controlling mechanism should be capable of accurate adjustment and of free and responsive action. In instruments of this class heretofore the operating parts of the mechanism have been constructed of wood, which is liable to become checked or warped by changes in temperature and in the humidity of the atmosphere, rendering the mechanism defective in its operation.

It is the object of my present invention to so construct the vacuum chamber, valve chamber, and connected primary and motor pneumatics as will enable these portions to be constructed of metal in separate and detached parts, each complete in itself and capable of being detachably connected by air tight oints, whereby the efficiency and durability of the structure is increased, and itis a further object of my invention to ren der the structure more compact, with each part readily accessible, allowing the same to be removed for repair or replaced by new parts.

Referring to the accompanying drawing 1 denotes a portion of the inclosing case, 2, 3 rolls for carrying the perforated music sheet 4. The tracker board is denoted at 5 having a series of openings, one of which is shown at 6, through which air is admitted when the opening is uncovered by a perforation in the music sheet 4. Air entering through the opening 6 in the tracker board is conducted by pipes forming an air conduit 7, to an air chamber 8, inclosed in a cup shaped shell 9, which contains a flexible diaphragm 10 forming the primary pneumatic, to which is attached a tollower11,supporting a valve stem 12, which carries the valve disks 13 and 14 inclosed in a tube 15, forming the valve body, beneath which is placed an inverted shell 16, containing a flexible diaphragm 17 and forming the motor pneumatic upon which rests a 01- lower 18, connected by a link 19, with a le ver 20 pivoted at one end to a stud 21, which is attached to and suspended beneath the valve body 15. The free end of the lever 20 is connected by a link 22 with one end of a pivoted lever 23 and forming the key striker. Only a portion of the key striker is shown, as its construction and operation will be well understood, it being well known in this class of instruments, and consisting of a straight lever pivoted midway its length, with its rear end connected by a link 22 with the lever 20, and its opposite end adapted to strike upon and depress a key of a piano as the actuating lever 20 is moved in the direction of the arrow a, Fig. 1.

The cup shaped shell 9 is provided with a tubular extension 24, provided with an external screw thread which engages an internal screw thread 25 on the end of the valve body 15, by which the primary pneumatic and the valve body are united and held in alinement. The valve body 15 is provided near its screw threaded end with an exterior flange 26, and between the flange 26 and the shell 9 of the primary pneumatic is clamped a rectangular metallic box 27, with the joints rendered air tight by the employment of elastic gaskets 28 and 29 which are compressed against the parallel sides of the metallic box 27. The box 27 incloses a vacuum chamber 30 which communicates with the space on one side of the diaphragm 10 by means of holes 31 in the tubular extension 24 of the primary pneumatic. The valve body 15 is provided with transverse plates having valve seats 32 and 33 and also central openings 33 and 33", one of which is closed by the valve disk 13 and the other by the valve disk 14. The opening through the valve seat 32 closed by the disk 13 affords a communication between the valve body 15 and the vacuum chamber 30, and the opening through the valve seat 33, which is closed by the valve disk 14 atfords a communication between the valve body 15 and the outside air. The valve disks 13 and 14 are carried on the valve stem 12 in proper position so the longitudinal movement of the valve stem in one direction will close the opening in the valve seat 32, and open that in the valve seat 33, and the movement of the valve stem in the opposite direction will close the opening in the valve seat 33 and open that in the valve seat 32. Between the valve disk 14 and the curved brace 34, attached to the valve seat 33, is a spiral spring 35 with its tension applied to normally hold the valve disk 13 firmly against its valve seat, as represented in Fig. 1, and with the valve body 15 communicating with the outside air. In this position of the valve disks 13 and 14 the normal air pressure is maintained on both sides of the flexible diaphragm 17, and the weight of the follower l8 and connected lever will serve to depress the connected end of the key striker 23 and elevate its opposite end, allowing the key of the piano in contact therewith to assume its normal or raised position.

The box 27 containing the vacuum chamber 30 extends across the machine and may contain several primary pneumatics and valve bodies, but as they are all duplicates of each other it is necessary to describe the construction and operation of but one. In addition to the box 27 with its series of primary pneumatics, other boxes and pneumatics precisely similar in construction are arranged immediately beneath the box 27, a portion of two such boxes being shown at 27 and 27 with their edges in contactand each forming a support for the one immediately above it. The box 27 inclosing the vacuum chamber 30, communicates at one end through a short flanged thimble 36, with the air chamber 37 inclosed in a metallic box 38 which extends vertically downward transversely across the ends of the vacuum chamber boxes, with which it communicates through similar flanged thimbles, the box 27 being connected by a thimble 39, and the box 27 by a thimble 40, each of the thimbles inclosing openings 41 and 42 in alinement with each other in the walls of the vacuum chamber boxes and the vertical box 38. The connecting thimble 36 is flanged at opposite ends which bear against gaskets 43 and 44 forming an air tight joint between the flanged ends of the thimble and the connected metallic boxes, the three being clamped together by a bolt 45 and nut 46. Each of the vacuum chamber boxes is similarly attached at one end to the vertical metallic box 38 and likewise to a duplicate vertical box at the opposite end, and these transverse vertical boxes thereby serve to unite the several vacuum chamber boxes into a single rigid structure, and by attaching the vertical boxes 38 to the case of the machine by means of suitable brackets, one of which is shown at 47, Fig. 1, a firm support is afiorded to the operative mechanism.

The air conduit 7 leading from the opening 6 in the tracker board to the primary pneumatic is provided with a small vent hole 48, communicating with a chamber 49 which extends across the machine parallel with the vacuum chamber boxes and communicates at its ends with the vertical boxes 38. The boxes 38 at their lower ends communicate through pipes, one of which is shown at 50, Fig. 1, with a pumping or exhaust bellows, not shown, which by the operation of a pedal maintains a partial vacuum throughout the vertical boxes 38 and the various air passages and chambers directly connected therewith, namely, the air chamber 49, the several vacuum chambers and the spaces between the diaphragms 10 of the primary pneumatics and the passages closed by the valve disks 13, and as the hole 6 in the tracker board is closed by the music sheet, air is exhausted through the vent hole 48 from the air conduit 7, and the shells 9 thereby maintaining a similar partial vacuum on both sides of the diaphragms 10 of the primary pneumatics enabling the tension of the spring 35 to hold the valve disks 13 firmly against their valve seats and prevent air from flowing into the vacuum chambers through the valve bodies. If a perforation in the music sheet 4 is now brought by the movement of the rolls over the opening 6 of the tracker board, a current of air immediately rushes through the conduit 7 in a volume in excess of the capacity of the vent hole 48, and passing into the shell 9 acts against the diaphragm 10 to move the valve stem 12, compressing the spring 35 and opening the valve 13 and .closing the valve 14. The connection between the motor pneumatic and the outside air is thus closed and a connection established through the valve body between the motor pneumatic and the vacuum chamber 30, thereby producing a partial vacuum in the motor pneumatic causing the normal air pressure against the lower side of the diaphragm to raise the same and rock the lever 20 in the direction of the arrow a, Fig. 1, thereby rocking the key striker 23 and depressing the key of the piano.

The shells 16 of the motor pneumatics are provided with screw threaded tubular shanks 51, which are screwed into thimbles 52, provided at one end with a curved flange 53,which is brazed to the underside of the valve body 15. The opposite end of the thimble 52 is provided with a flange be tween which and the shell 16 I insert an elastic gasket 55, thereby making an air tight joint between the motor pneumatic and the valve body and rendering the motor pneumatic readily detachable from the valve body. The air conduit from the opening 6 in the tracker board to the shell 9 of the primary pneumatic is formed by several pipes which comprise removable sections 56 and 57, preferably of rubber tubing, which enables the primary pneumatics to be disconnected from the tracker board allowing the primary pneumatics to be rotated and unscrewed from the valve bodies 15. As each of the primary pneumatics is readily accessible from the front of the machine, as shown in Fig. 2, any one of the primary pneumatics and its connected valve body and motor pneumatic can be readily removed from the instrument without disturbing any other part.

In Fig. 5 I have shown a modified form of construction by which the valve body and primary pneumatic are each individually united to the metallic box inclosing the. vacuum chamber and it possesses the advantage of enabling either the primary pneumatic or the valve body to be removed without disturbing the other. In the modified form shown in Fig. 5 a metal box inclosing a valve chamber is represented at 58 having openings in its opposite walls communicating with a primary pneumatic 59 and a valve body 60. In one of the openings in the box 58 I insert a collar 61 having an internal screw thread to receive the screw threaded tubular section 62 of the primary pneumatic. The collar 61 is provided with a flange 63 by which it is brazed to the side of the box 58 and between which and primary pneumatic I insert a yielding gasket 64. \Vithin the opening in the opposite wall of the box 58 I place a collar 55, having a flange 66, which is brazed to the inside of the box 58 and provided with an exterior screw thread to receive a screw threaded sleeve 67. The sleeve 67 is provided with an interior flange 68 which incloses an exterior flange 69 on the valve body 60, and between the flanges 68 and 69 I insert a yielding gasket 70. ithin the valve body is located the valve 13 designed to rest on the seat 13, the former being carried by the valve stem 12 the same as in the construction heretofore described. By the construction shown in Fig. 5 the primary pneumatic 59 may be readily withdrawn by unscrewing it from the screw threaded collar 61, and the valve body 60 may be removed by unscrewing the flanged sleeve 67.

The flexible diaphragm"17 of the motor pneumatic is protected by a cover 71 formed of sheet metal stamped into suitable shape to conform to the normal shape of the flexible diaphragm 17. The cover 71. is attached at its edge to the edge of the inverted shell 16, and is provided with a central opening 72 of suflicient size to admit air at its normal pressure to the under side of the diaphragm, in order that the air pressure may be applied to the entire surface of the flexible diaphragm 17. The cover 71 is provided with a series of indentations 73 by which the metal is raised in spots on the inner side of the cover to lift the diaphragm sufiiciently to provide an intervening air space between the diaphragm and cover. The employment of covers 71 for the diaphragms of the motor pneumatics is designed to protect the diaphragms from accidental injury.

What I claim as my invention and desire to secure by Letters Patent is 1. In a pneumatic action for musical instruments, the combination with a box inclosing a vacuum chamber, of a primary pneumatic outside said box and detachably attached thereto, a tubular valve body outside said box and detachably attached thereto opposite said primary pneumatic, said valve body communicating with said vacuum chamber at one end and having its opposite end open, valves contained in said valve body, and a valve stem extending through said valve body and said vacuum chamber and carrying said valves, a motor pneumatic supported by the valve body, and means whereby the motor pneumatic has communication with the vacuum chamber.

2. In a pneumatic action for musical instruments, the combination with a box inclosing a vacuum chamber, of a primary pneumatic removably held on one side of said box, a tubular valve body having one end detachably attached to said box and communicating with said vacuum chamber and having an opening in its free end, a valve for closing the free end of said valve body, a valve for closing the communication between the valve body and the vacuum chamber, a valve stem carrying said valves, and operatively connected with said primary pneumatic, and a motor pneumatic supported by said valve body and communicating there with between said valves and with the vacuum chamber.

3. In a pneumatic action for musical instruments, the combination of a box inclosing a vacuum chamber, of a tubular valve body removably held on one side of said box and having an opening for a motor pneumatic, a collar having a curved flange at one end by which it is attached to said valve body, a flange at its opposite end, and an internal screw thread, of a motor pneumatic having a screw threaded extension entering said collar, substantially as described.

4. In a pneumatic action for musical in struments, the combination of a series of boxes each inclosing a vacuum chamber, a box extending transversely across the ends of said vacuum chamber boxes, and forming an air passage for the exhaustion of air from said vacuum chambers, a series of flanged thimblcs interposed between said air pas sage box and said vacuum chamberboxes and communicating with each, and bolts passing through said thimbles and connected boxes, substantially as described.

5. In a pneumatic action for musical instruments, the combination of a series of boxes supported by and resting one upon the other in a vertical plane and each inclosing a vacuum chamber, and a series of primary pneumatics supported by the Vertical walls of said boxes on one side, a series of valve bodies supported by the vertical walls of said boxes on the side opposite said pneumatics, and a series of motor pneumatics supported by said valved bodies and communicating with the vacuum chambers.

6. The combination with a cup-shaped shell and a flexible diaphragm held Within said shell, of a cover for said diaphragm provided with an opening for the admission of air to the diaphragm, said cover having raised surfaces arranged to contact with and support the diaphragm.

7. In a pneumatic action for musical instruments, the combination of a series of boxes supported by and resting upon one another in a vertical plane and each inclosing a vacuum chamber, a series of primary pneumatics supported by the vertical walls of said boxes on one side, and a series of valve bodies supported by the vertical walls of said boxes on the side opposite said pneumatics, said valve bodies and pneumatics being of independent metallic formation and removable.

8. In a pneumatic action for musical instruments, a vacuum chamber having oppositely disposed openings in its respective walls, a primary pneumatic having an extension sleeved within said opening, and a valve chamber having direct connection with the said extension through the opening in the opposite wall of the vacuum chamber.

9. In a pneumatic action for musical instruments, the combination with a box inclosing a vacuum chamber, of a primary pneumatic outside said box and detachably attached thereto, a tubular valve body outside said box and detachably attached opposite said primary pneumatic, said valve body communicating with said vacuum chamber at one end and having its opposite end open, valves contained in said valve body, and a valve stem extending through said valve body and said vacuum chamber and carrying said valves.

10. In a pneumatic action for musical instruments, the combination of a series of vacuum chambers, a box extending across the ends of a plurality of said chambers and forming an air passage for the exhaustion of air "from said vacuum chambers, and a series of conduits leading from the respective chambers to the air passage box.

11. In a pneumatic action for musical instruments, the combination of a series of vacuum chambers, a box extending across the end of a plurality of said chambers and forming an air passage for the exhaustion of air from said vacuum chambers, and thimbles contacting at their respective ends with the vacuum chambers and said air passage box and communicating with each.

12. In a pneumatic action for musical instruments, the combination of a series of vacuum chambers, a box extending across the ends of a plurality of said chambers and forming an air passage for the exhaustion of air from said vacuum chambers, and thimbles having flanged terminals contacting with said chambers and said box respectively and affording communication therebetWeen.

13. In a pneumatic act-ion for musical instruments, the combination of a series of vacuum chambers, a box extending across the ends of a plurality of said chambers and forming an air passage for the exhaustion of air from said vacuum chambers, and thimbles having flanged terminals contacting With said chambers and said box respectively and alfording communication therebetvveen, and means for connecting the thimbles With the chambers and box.

14. In a pneumatic action for musical instruments, the combination of a plurality of vacuum chambers, a box extending across the ends of the said chambers and forming an air passage for the exhaustion of the air from the vacuum chambers, and tubular conduits one for each chamber establishing communication between said chambers and the air passage box, and means for mounting the conduits in position comprising a bolt extending through the conduits and connected to the chambers and box.

15. In a pneumatic action for musical instruments, the combination of a series of boxes supported by and resting one upon another in a vertical plane and each inclosing a vacuum chamber, a series of primary pneumatics supported by the vertical Walls of said boxes on one side, and a series of valve bodies supported by the vertical Walls of said boxes on the side opposite said pneumatics, the said valve bodies and pneumatics being independently removable.

Dated this 8th day of July 1903.

MORRIS S. l/VRIGHT.

Witnesses:

RUFUS B. FOWLER, PENELOPE CoMBERBAoH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

